safety and immune response to two doses of rden2/4delta30 dengue vaccine

Conditions: Dengue Fever

Summary: dengue fever, caused by dengue viruses, is a major health problem in the tropical and subtropical regions of the world. the purpose of this study is to test the safety of and immune response to a new dengue virus vaccine in healthy adults.

dengue viruses, which cause dengue fever and dengue shock syndrome, are a major cause of morbidity and mortality in several of the world's tropical and subtropical regions. the rden2/4delta30(me) vaccine is a live attenuated dengue virus vaccine that may be protective against dengue virus serotype 2 (den2). the purpose of this study is to evaluate the safety and immunogenicity of the rden2/4delta30(me) vaccine in healthy adults. this study will last approximately 5 to 7 months with 25 study visits. participants will be randomly assigned into one of two cohorts. participants in cohort 1 will receive an injection of rden2/4delta30(me) or placebo vaccine at days 0 and 180. participants in cohort 2 will receive an injection of rden2/4delta30(me) or placebo vaccine at days 0 and 120. participants will be asked to record their temperature in a diary for 16 days after each vaccination. at each study visit a physical examination, symptom history, and blood and urine collection will occur.

Eligibility criteria:
inclusion criteria: * good general health as determined by means of the screening procedures. * available for the duration of the study (32 weeks for cohort 1 and 23 weeks for cohort 2) * willing to use effective methods of contraception exclusion criteria: * evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history, physical examination, and/or laboratory studies * behavioral, cognitive, or psychiatric disease that in the opinion of the investigator will affect the ability of the volunteer to understand and cooperate with the requirements of the study protocol * neutropenia as defined by an anc ≤1500/mm3 * alt level above the laboratory-defined upper limit of normal * serum creatinine level above the laboratory-defined upper limit of normal * any other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol. * medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months * history of a severe allergic reaction or anaphylaxis * severe asthma (emergency room visit or hospitalization within the last 6 months) * positive hiv-1 serology by screening and confirmatory assays * positive for hepatitis c virus (hcv) by screening and confirmatory assays * positive hepatitis b surface antigen (hbsag) by enzyme-linked immunosorbent assay (elisa) * known immunodeficiency syndrome * use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of starting this study * receipt of a live vaccine within the 4 weeks or a killed vaccine within the 2 weeks prior to entry into the study * has had spleen surgically removed * receipt of blood products within the 6 months prior to study entry * history or serologic evidence of previous dengue virus infection or other flavivirus infection (e.g. yellow fever virus, st. louis encephalitis, west nile virus). * previous receipt of yellow fever or dengue vaccine (licensed or experimental) * persons who have received any investigational agent in the 30 days prior to study entry * persons who have definite plans to travel to a dengue endemic area during the study